On 27 May OVDAS-SERNAGEOMIN reported that seismicity at Calbuco fluctuated at low levels and continued to decline. According to ONEMI, the 10-km evacuation zone remained in effect, with controlled access to some communities allowed for part of the day; about 500 people remained displaced. On 28 May OVDAS-SERNAGEOMIN lowered the Alert Level remained to Yellow (the second lowest level on a four-color scale).

On the morning of 12 August, the ~250,000 residents of Puerto Montt (35 km SW) and Puerto Varas (36 km SW) were alarmed by strong fumarolic emissions from the 1.5-km-diameter main crater of Calbuco. In May 1995 a weak fumarole was noticed and filmed from a helicopter. Prior to that, Calbuco had showed no signs of activity since a 1972 eruption that lasted for ~4 hours.

Calbuco is a very explosive late Pleistocene to Holocene andesitic volcano S of Lake Llanquihue that underwent edifice collapse in the late Pleistocene, producing a volcanic debris avalanche that reached the lake. One of the largest historical eruptions in southern Chile took place from Calbuco in 1893-1894. Violent eruptions ejected 30-cm bombs to distances of 8 km from the crater, accompanied by voluminous hot lahars. Several days of darkness occurred in San Carlos de Bariloche, Argentina (>100 km SE). Strong explosions occurred in April 1917, and a lava dome formed in the crater accompanied by hot lahars. Another short explosive eruption in January 1929 also included an apparent pyroclastic flow and a lava flow. The last major eruption of Calbuco, in 1961, sent ash columns 12-15 km high and produced plumes that dispersed mainly to the SE as far as Bariloche; two lava flows were also emitted.

Weekly Reports - Index

On 27 May OVDAS-SERNAGEOMIN reported that seismicity at Calbuco fluctuated at low levels and continued to decline. According to ONEMI, the 10-km evacuation zone remained in effect, with controlled access to some communities allowed for part of the day; about 500 people remained displaced. On 28 May OVDAS-SERNAGEOMIN lowered the Alert Level remained to Yellow (the second lowest level on a four-color scale).

OVDAS-SERNAGEOMIN reported that during 20-26 May activity at Calbuco fluctuated at low levels and continued to decline. Inclement weather prevented observations of the summit area on most days; white plumes were observed rising 300-400 m and drifting SE during 24-26 May, and incandescence at the crater was observed at night during 25-26 May. According to ONEMI, the number of evacuees within the 20-km evacuation zone remained at 6,685 on 26 May. The Alert Level remained at Orange (the second highest level on a four-color scale), and the 10-km-radius exclusion zone continued to be in effect.

OVDAS-SERNAGEOMIN reported that during 13-19 May activity at Calbuco fluctuated at low levels and continued to decline. Inclement weather prevented daily observations of the summit area, although incandescence at the crater was observed during 17-18 May. According to ONEMI, the number of evacuees within the 20-km evacuation zone remained at 6,685 on 18 May. On 19 May the Alert Level was lowered to Orange (the second highest level on a four-color scale), and the exclusion zone was changed to a 10-km radius.

OVDAS-SERNAGEOMIN reported that on 6 May activity at Calbuco fluctuated; a sudden increase of tremor that began at 1304 and lasted two hours was accompanied by increased gas-and-ash emissions. During 7-11 May the gas-and-ash emissions were steady and low (less than 1 km), and drifted E, SE, and S; inclement weather prevented observations during 8-10 and 12 May. Moderate levels of tremor were detected through 9 May, and then decreased to low levels through 12 May. According to ONEMI, the number of evacuees within the 20-km evacuation zone remained at 6,685 on 12 May. In addition 3,221 animals, including sheep, goats, cows, and horses, had been evacuated. The Alert Level remained at Red (the highest level on a four-color scale).

Satellite images showed that the aerosol plume from the initial few days of the eruption had traveled around the world once; faint layers of the plume were 14-16 km above parts of South America during 8-9 May.

OVDAS-SERNAGEOMIN reported that on 29 April a weak ash plume rose as high as 1.5 km above Calbuco and seismicity remained stable. An event that began at 1308 on 30 April produced an ash plume that rose 3-5 km and drifted SE. A small lahar in the Blanco River may have been caused by a pyroclastic flow. Tremor amplitude increased and became sustained after the event. On 2 May the number of earthquakes increased. Seismicity significantly increased on 3 May, characterized by a swarm of volcano-tectonic events, and then decreased afterwards. Seismicity was low and stable on 5 May. A plume rose less than 1 km during 1-3 May; cloud cover prevented visual observations of the volcano during 4-5 May. According to ONEMI, the number of evacuees totaled 6,685 on 5 May. The Alert Level remained at Red (the highest level on a four-color scale).

OVDAS-SERNAGEOMIN reported that an eruption from Calbuco began at 1804 on 22 April, prompting the Alert Level to be raised to Red (the highest level on a four-color scale) and causing a 20-km exclusion zone to be declared. The eruption was preceded by an hour-long period of volcano-tectonic events followed by long-period events; no increases in seismicity had been noted since 2009 when real-time seismic monitoring started. After a large seismic event detected at 1735, a 90 minute eruption generated a sub-Plinian, gray ash plume that rose 15 km above the main crater and drifted mainly ENE, although fine ash drifted N and NW. Column collapses occurred locally and radially, affecting the headwaters of major rivers. Residents within the exclusion zone, in Chamiza, Lago Chapo, and Correntoso sectors, and in the town of Puerto Montt, were ordered to evacuate. Several roads and bridges were impassable due to ashfall.

A larger second event on 23 April began at 0100, lasted six hours, and also generated a sub-Plinian ash plume that rose higher than 15 km and drifted N, NE, and E. Incandescent tephra was ejected as far as 5 km; deposits were concentrated to the N and NE, with thicknesses varying from tens of centimeters in the Región de Los Lagos to a few millimeters in the Los Ríos and La Araucanía areas. Pyroclastic flows traveled a maximum distance of 7 km and lahars traveled 15 km. Pumice fell in Región de Los Lagos, and ash fell in Los Ríos and La Araucanía. Tephra also fell in Argentine territory, NE of the volcano. Scientists aboard an overflight observed ash emissions from at least six vents on the W, SW, and S sides of the old lava dome. About 5,000 people had been evacuated and ONEMI warned people not to go within 200 m of drainages due to lahar hazards. At around 2330 a third phase of surficial activity was noted; ash plumes rose 2 km and drifted NE and E. On 24 April the ash plume continued to rise 2 km and explosions were detected. News articles noted that international flights in and out of several major cities were delayed or canceled. According to a news article, ash from the eruption reached southern Brazil on 25 April prompting some airlines to cancel flights using airports in Santiago, Buenos Aires, and Montevideo. Some houses in areas near the volcano collapsed from the weight of the ash. The ash plume persisted on 25 April, but rose to a lower height of 400 m, and sporadic explosions were detected. Seismicity declined during 26-27 April; the ash plume rose 1.5 km, and drifted NE and SE. ONEMI noted on 27 April that 246 of 4,514 evacuees were in shelters; the number of displaced people had peaked at 6,514 during 24-26 April.

A satellite-based estimate of sulfur dioxide emissions was 0.3-0.4Tg by 28 April, detected as high as 21 km altitude. Although most ash had fallen out of the plume over Chile and Argentina, some may have remained in the stratospheric plume drifting around the globe; the leading edge of the gas plume had reached the Indian Ocean, S of Madagascar.

Information is preliminary and subject to change. All times are local (unless otherwise noted)

On the morning of 12 August, the ~250,000 residents of Puerto Montt (35 km SW) and Puerto Varas (36 km SW) were alarmed by strong fumarolic emissions from the 1.5-km-diameter main crater of Calbuco. In May 1995 a weak fumarole was noticed and filmed from a helicopter. Prior to that, Calbuco had showed no signs of activity since a 1972 eruption that lasted for ~4 hours.

Calbuco is a very explosive late Pleistocene to Holocene andesitic volcano S of Lake Llanquihue that underwent edifice collapse in the late Pleistocene, producing a volcanic debris avalanche that reached the lake. One of the largest historical eruptions in southern Chile took place from Calbuco in 1893-1894. Violent eruptions ejected 30-cm bombs to distances of 8 km from the crater, accompanied by voluminous hot lahars. Several days of darkness occurred in San Carlos de Bariloche, Argentina (>100 km SE). Strong explosions occurred in April 1917, and a lava dome formed in the crater accompanied by hot lahars. Another short explosive eruption in January 1929 also included an apparent pyroclastic flow and a lava flow. The last major eruption of Calbuco, in 1961, sent ash columns 12-15 km high and produced plumes that dispersed mainly to the SE as far as Bariloche; two lava flows were also emitted.

Volcano Types

Tectonic Setting

Subduction zoneContinental crust (> 25 km)

Rock Types

Major
Andesite / Basaltic Andesite

Population

Within 5 kmWithin 10 kmWithin 30 kmWithin 100 km

70
871
32,265
575,233

Geological Summary

Along with its neighbor Osorno, Calbuco is one of the most active volcanoes of the southern Chilean Andes. The isolated late-Pleistocene to Holocene andesitic volcano rises to 2003 m south of Lake Llanquihué in the Chilean lake district. Guanahuca, Guenauca, Huanauca, and Huanaque, all listed as synonyms of Calbuco (Catalog of Active Volcanoes of the World), are actually synonyms of nearby Osorno volcano (Moreno 1985, pers. comm.). The 2003-m-high Calbuco is elongated in a SW-NE direction and is capped by a 400-500 m wide summit crater. The complex evolution of Calbuco included edifice collapse of an intermediate edifice during the late Pleistocene that produced a 3 cu km debris avalanche that reached the lake. Calbuco has erupted frequently during the Holocene, and one of the largest historical eruptions in southern Chile took place from Calbuco in 1893-1894 and concluded with lava dome emplacement. Subsequent eruptions have enlarged the lava-dome complex in the summit crater.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Synonyms

Quellaipe | Nauga | Quellaype

Cones

Feature Name

Feature Type

Elevation

Latitude

Longitude

Huenú-Huenú

Stratovolcano

Photo Gallery

The symmetrical, glacier-clad Osorno stratovolcano forms a renowned landmark between Todos Los Santos and Llanguihue lakes. It is seen here from the north, with Calbuco volcano visible at the extreme right. The 2652-m-high Osorno is one of the most active volcanoes of the southern Chilean Andes. Flank scoria cones and fissure vents, primarily on the west and SW sides, have produced lava flows that reached Lago Llanguihue. Historical eruptions have originated from both summit and flank vents.

Photo by Hugo Moreno (University of Chile).

Calbuco is one of the most active volcanoes of the southern Chilean Andes. The isolated volcano rises to 2003 m south of Lake Llanquihue, which is visible at the upper right. The summit ridge (center) of the volcano is the remnant of an older volcano that collapsed during the late Pleistocene and produced a 3 cu km debris avalanche that reached the lake. Subsequent eruptions generated andesitic lava flows, breccias, and tuffs that filled the scarp and were subsequently topped by an historical lava-dome complex (right center).

Photo by Hugo Moreno (University of Chile).

Along with its neighbor Osorno (upper left), Calbuco is one of the most active volcanoes of the southern Chilean Andes. The summit of Calbuco, seen at the left in this view from the SW, is the remnant of an older volcano that collapsed during the late Pleistocene, producing a debris avalanche that swept NNW into Lake Llanquihue. The smooth, snow-covered summit at the right is a young, historical lava-dome complex that postdates one of the largest historical eruptions in southern Chile during 1893-1894.

Photo by Hugo Moreno (University of Chile).

References

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.

EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).